Most frozen vegetables are sold to the consumer packaged either in relatively large plastic bags intended for freezer storage as portions of the product are heated and consumed, or in smaller cartons enclosing a quantity generally appropriate for consumption by a typical family at one meal. The cartons are typically constructed of blanked waterproof paperboard that is coated with polyethylene plastic or wax and include flaps that are folded and secured with an adhesive to hermetically seal the container, thereby ensuring product freshness.
Recognizing that it is desirable to minimize the number of dishes required in preparing a meal, microwavable and/or ovenable food packaging containers have been developed that may be placed directly in an oven for heating their enclosed product. Containers such as these may be folded from a blank which includes gusseted corners so that the bottom of the container thus constructed forms a leakproof tray. After the container is filled with the food product through the open top, the top is closed over the food and sealed to the lower portion. The top typically includes a flap that may be torn back by the consumer to expose the product and/or to add water, butter or seasonings either during or before starting the cooking process. A tab on the end of the flap may be inserted into a slot provided on the front sidewall of the container, leaving a wedge-shaped gap between the flap and the top through which steam may escape. Although certain food products may require that steam be allowed to escape during the cooking process, for the majority of food products, allowing the steam to escape is undesirable because it extends the cooking time. If the flap could be more tightly reclosed, the steam thus trapped inside the container would tend to cook the product faster.
Rather specialized machinery, not presently installed in most food packaging facilities, is required to fold, fill and seal the above-described top fillable, microwavable and/or ovenable container. The typical packaging facility has machinery in place for folding, filling and sealing conventional end fillable containers. However, such containers are not microwavable or ovenable, in part, because they are not leakproof. Conventional end fillable containers are provided with four simple flaps on each end, one of the flaps usually being relatively narrow (i.e., less than one fourth the width of the opposite flap on that end). Even if such flaps were thermally sealed, liquid would certainly leak through the corners once the product was warmed in an oven.
In consideration of the above-described problems of known prior art food packaging containers, it is a primary object of this invention to provide an end fillable container which may be placed directly in a microwave and/or conventional oven for heating the product contained therein.
Further objects of this invention are to provide an end fillable food packaging container that may be opened by the consumer, yet remain leakproof while used to hold food heated in a microwave and/or conventional oven; to provide an end fillable container that may be folded, filled and sealed on presently available machinery that is designed to be used with conventional end fillable containers (requiring only minor changes to the machinery); to provide a method for folding, filling and sealing an end fillable microwavable and/or ovenable container; to provide a flap on an end fillable microwavable and/or ovenable container that may be more tightly reclosed by a consumer of the product packaged therein, as compared to the flap provided on conventional top filled microwavable, ovenable containers; to provide such a container effective to store "left over" food products that have been partially consumed; to provide such a container which when reclosed, is easier to handle with less chance of spilling its contents; to provide a container in which food may be cooked more quickly than in conventional containers which vent steam; to provide a container with more conveniently displayed cooking instructions and with graphics unmarred by tear lines; and, to provide an end fillable microwavable and/or ovenable container with a conventional reclosable flap for use in heating products for which it is preferable that the flap not be tightly closed, so that steam may escape during the cooking process.
These and other objects of the invention will be apparent to those of ordinary skill in the art to which this invention pertains, by reference to the attached drawings and the disclosure of the preferred embodiments that follow hereinbelow.